// corresponding entry in the `dims` array must be -1.
//
// This does not overwrite the existing shape associated with `output`,
// but merges the input shape with the existing shape.  For example,
// setting a shape of [-1, 2] with an existing shape [2, -1] would set
// a final shape of [2, 2] based on shape merging semantics.
//
// Returns an error into `status` if:

                            TF_WritableFile* file, TF_Status* status);

  /// Creates an object to append to a file with the specified `path`.
  ///
  /// If the file doesn't exists, it is first created with empty contents.
  /// The `file` object must only be accessed by one thread at a time.
  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` if `file` was updated.